White Sox reliever Nate Jones said he had heard of bullpens, “but never heard of (bullpen and) an i-n-g,” while Cubs swingman Mike Montgomery asked if it was “like throwing our side sessions?”

Others understood the concept but declined to use the word in public.

“I don’t subscribe to titles,” Angels general manager Billy Eppler said. “I know that has become a popular term.”

There is no official definition of bullpenning in the dictionary, but Dodgers manager Dave Roberts, one of the foremost practitioners of the art, believes it comes down to two words:

Counting outs.

“It’s certainly more matchup-based, and outside the starter, teams are counting outs more,” Roberts said. “So you can look at it as counting outs, or ‘bullpenning.’

“You look at last year. I know in the National League, teams across the board were carrying eight relievers for the most part, so that speaks to bullpenning.”

Managing bullpens is usually the most important task of a manager, and having more relievers to choose from adds to the degree of difficulty. Will every move work out?

But the game has evolved to the point where every team’s bullpen has multiple relievers throwing in the upper 90s, and statistical analysis can tell you exactly when every starter’s expiration date is during any given game.

Instead of waiting for the starter to get in trouble, an early hook brings in fresh arms to get through four or more innings.

Generally speaking, it’s used mostly in the postseason when games are more important and relievers can be handled differently because the season is ending and they can rest their arms all winter. But the importance of bullpen roles obviously has increased substantially over the last decade.

“I don’t know why, but I guess there are just guys with unbelievable arms in bullpens,” Montgomery said. “And teams, the way the game is going toward (employing) sabermetrics, it’s like ‘OK, two times through the lineup and the starter is done.’

“Look, sometimes that works. Sometimes it doesn’t. I think teams, if a starter is going well, sometimes they pull him too quick, because bullpens are so good. But if bullpens are worn out, they’re not going to be too good.”

The Rockies spent $106 million on their bullpen this offseason, signing former Cubs closer Wade Davis to a three-year, $52 million deal, adding Bryan Shaw and re-signing Jake McGee. Along with Mike Dunn and Adam Ottavino, the bullpen could be more important than the Rockies rotation.

“Are we trying to get the best bullpen we can? Yeah,” Black said. “I’ve heard some different definitions of bullpenning, but I will say I know the importance of starting pitching as it relates to a 162-game schedule.

“I know the importance of durability and starter performance, and what that means to a bullpen. Am I a proponent of good starting pitching and depth and starting pitcher innings? Absolutely. The better you are in that department, the better you can be in your bullpen.

“I’m not one who discounts starting pitching and starts using your pen earlier in games because I know over six months in the everyday game we play, you need length out of your starters You can’t throw relief pitchers as much as some people think you can.”

That’s where the new 10-day disabled list comes in. Shortened from the traditional 15 days last year, the 10-day DL can be used to maintain a fresher staff because general arm soreness is an injury whether the pitcher can pitch through it or not. Starters can get rest and miss only a start or two.

The Dodgers had 38 total DL stints in 2017, according to rosterresource.com, leading the majors. Some accused them of “gaming” the system. The Cubs, whom the Dodgers beat 4-1 in the National League Championship Series, had 12 DL stints.

Brandon Morrow, now the Cubs’ closer, was a major part of the Dodgers’ bullpen strategy last year and pitched in all seven games in the World Series. Roberts didn’t hesitate to yank starters early, whether they were effective or not.

“They had a bullpenning plan for sure, and most days stuck to their guns,” Morrow said. “You saw him take Rich Hill out early a couple of games in the playoffs. All our guys were going good, so there was nothing backfiring.

“I’ve seen it with a few different teams, and seems to be working, at least if you have the personnel to do it.”

Roberts doesn’t envision a future in which every starter is programmed to go only four or five innings and the rest of the game is simply matching up the pen to the opposing lineup.

“The value of a guy going six innings or deep in a game and still being effective, those guys are hard to come by,” he said. “I think where we’re at right now will hold for a while, because of the health of the guys, and it’s a very copy-cat league.

“The success of certain teams, how they sort of manage the pens, teams are really committed to the eight-man pen. They’re committed to guys who can go two innings. They’re obviously aware of the (risks of facing lineups) the third time through, and things like that, so I think there’s going to more of what we saw last year.”

Perhaps the future consists of virtual taxi squads in which pitchers are shuttled up and down constantly from Triple A to the majors and the top starters all have “rest” periods scheduled into the season.

“You need depth and talent at Triple A, and guys with options where you can rotate a fresh arm in and out, and then you get into creative use of the 10-day disabled list,” Black said. “It becomes a new dynamic on how you run your pitching.

“I don’t think we’re there yet, but we saw some things in the playoffs, the last couple of years. It can make sense in the playoffs because there’s an end to it. You have a game or two more (to play), and you can get by. But you can’t do that on April 5.

“The game would have to drastically take a turn to that model, and it would take time for that model to be set in place.

“Does it look like there’s some momentum toward that? Yeah, you could say the playoffs the last couple of years have shown that. I still think we’re not there yet because bullpen depth and arms and depth in the minor leagues isn’t where it needs to be.”

Two-hundred innings or more of work was once the stated goal of most starters in spring training. Last year 15 starters compiled 200 or more innings, fewer than half the number (34) from the 2014 season.

That number isn’t going up any time soon.

“No doubt,” Black said. “That’s our fault. There’s more of that for sure.”

“If a starter can go seven innings, it’s a win for everybody,” Montgomery said. “It used to be if a starter went eight, that’s good. Now it’s like, ‘We’ll take seven if we can get it.’”

The trend toward the increasing usage of relievers means managing by the gut is riskier than ever. If your analytical data suggests the starter is going to tire the third time around the lineup, even if he’s still dealing now, are you going to ignore it?

“Playing probabilities is probably a good thing,” Eppler said. “You go into Vegas and you want to start betting at the craps table, and you kind of play the odds. That’s what a dice roll is, right? If you play odds, that can help you be a guide.

“No doubt that intuition comes in, but there’s also a workload aspect, and understanding how much or even how many times they have been up (warming up in the bullpen).

“Like in the NFL, if a team gets a matchup of a speedy wide receiver and an outside linebacker happens to be covering him, that’s an important matchup to scrutinize or take advantage of. You’re presented with that in baseball and (if) you have the flexibility with your personnel to maximize your win probability (you can take) advantage of that matchup.”

Bochy, an old-school type, said there always will be room for both styles of decision-making — by data or by gut instinct.

“The numbers, they’re so valuable, too,” he said. “There are a lot of variables involved when you talk about numbers, but at the same time I don’t think we ever get away from our gut, and what’s inside the gut of the player.”

Montgomery, who was lifted from a start in July after 84 pitches despite allowing just two hits and a walk over six innings, said the stats are misleading sometimes, citing the smaller sample size of a pitcher facing a particular hitter for a third time in a game.

“We have got to be careful of letting the stats dictate the game,” he said. “There’s a large element where you have to have (managers and pitching coaches) who have good feel and really know what’s going on.

Of course, someone like Kluber, Chris Sale, Clayton Kershaw or Madison Bumgarner will get the benefit of the doubt more than a fifth starter would.

“It’s something you earn,” said Morrow, a former starter. “I don’t think you let your No. 5 starter face a lineup a third time, I guess. The numbers maybe say everything goes through the roof at that point.

“There are definitely going to be the guys you lean on, (to) get seven or eight innings out of them. That’s going to save your bullpen. You have to have those guys to go bullpenning — those studs in the front.”

The studs in the front of the rotations always will be there. But the difference between a fifth starter and a middle innings “bridge” reliever is getting thinner and thinner, and there seems to be no going back.